Does biventricular conversion bring survival benefits to patients with an unbalanced...
Buratto, Edward;Khoo, Brandon;Ye, Xin Tao;Konstantinov, Igor E
2018-01-19 00:00:00
Letters to the Editor / European Journal of Cardio-Thoracic Surgery 1295 Yu et al. [1] are congratulated on their achievement of successfully closing al- 63 patients). They reported signiﬁcantly better survival with both biventricular legedly doubly committed ventricular septal defects in their series of 35 chil- repair and BiVC/BiVR strategies compared with SVP. dren recently reported in the journal. However, can we be sure that the However, their comparison was biased in favour of the BiVC/BiVR group in defects in question were truly doubly committed and juxta-arterial? The cri- several ways. Their time series analysis began at the time of ﬁrst stage palli- terion stated by the authors for diagnosis in this fashion was that the defect ation for SVP patients, while it began at the time of complete repair for BiVR/ should be ‘located at the 12.00 to 1.30 o’clock position in the parasternal BiVC patients, introducing a substantial survivorship bias. All patients who short axis view’. The criterion for diagnosis of the doubly committed and died prior to conversion were counted in the SVP group, leaving a selected juxta-arterial defect, however, is dependent on its borders rather than its lo- group of survivors to undergo BiVC/BiVR. Furthermore, patients who under- cation. However, the doubly committed variant is one of the defects that went SVP had higher rates of RV dominance (86.6% vs 61.9%), which had pre- can open to the outﬂow tract of the right ventricle and hence be detected viously been shown as a risk factor for death in SVP [2]. The SVP group also ‘in the 12.00 to 1.30 o’clock position’. In our recent experience in Cincinnati, had a much greater proportion of neonates (68.3% vs 3.2%), pulmonary vein of the defects detected on the basis of ‘conal hypoplasia’ and opening to the disease (31.7% vs 22.2%) and associated cardiac anomalies (43.9% vs 27.0%), right ventricle in this position when assessed echocardiographically, only a all of which have been associated with mortality. It is likely that the highly se- proportion was found to be doubly committed based on their borders, spe- lected group undergoing BiVC/BiVR would have had similarly good results ciﬁcally with ﬁbrous continuity between the leaﬂets of the aortic and pul- with the Fontan circulation. monary valves forming their cranial margin. It is not possible to distinguish In Melbourne, SVP is performed for patients with uAVSD who are not can- this feature of ﬁbrous continuity between the leaﬂets of the aortic and pul- didates for initial biventricular repair. We have recently published the long- monary valves in Fig. 3 as provided by Yu et al. [1]. The defects illustrated term outcomes of 139 uAVSD patients who underwent SVP [3]. We observed could just as well have been muscular outlet defects or perimembranous de- a similar attrition to Nathan et al. in the overall cohort, with a survival rate of fects with outlet extension. Because another criterion for exclusion was size 61.8% at 15 years. However, patients who achieved Fontan completion had <5 mm, it seems that the defects could have possessed completely muscular much better results than previously thought, with 83.5% freedom from death borders, and more so since the authors describe the pulmonary ‘annulus’ as and Fontan takedown at 15 years. This is similar to the results for BIVC/BiVR being ‘slightly higher than the aortic annulus’ in their patients. Had the de- reported by Nathan et al.[1], and it is likely that this cohort includes a similar fects truly been doubly committed, then the so-called ‘annuluses’ would degree of survivorship bias. have been at the same level. We do not mean to question the efﬁcacy of the Importantly, we observed that atrioventricular valve (AVV) regurgitation method proposed by the Chinese authors. If it is to be more widely used, is a major contributor to morbidity and mortality observed in these patients nonetheless, then surely it is crucial to provide more precise details of the [4, 5]. Patients with AVV regurgitation who achieved successful repair had criteria used so as to diagnose the defects as being doubly committed and much better outcomes than those with a signiﬁcant residual regurgitation [4]. juxta-arterial? Our focus is on improving the outcomes of AVV repair in these patients, as we believe this will be the key to improved survival. The work by Nathan et al. is important, and their results are encouraging. However, we emphasize that palliation with the Fontan circulation remains an REFERENCE important option for these patients. Advancements in techniques for repairing the AVV might further improve the outcomes for patients with uAVSD who [1] Yu J, Ma L, Ye J, Zhang Z, Li J, Yu J et al. Doubly committed ventricular sep- undergo SVP. tal defect closure using eccentric occlude via ultraminimal incision. Eur J Cardiothorac Surg 2017;52:805–9. Funding *Corresponding author. Cincinnati Children’s Hospital Medical Center, The Heart Institute, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. Tel: 513-803- This work was supported by a Reg Worcester Scholarship from the Royal 4538; e-mail: justin.tretter@cchmc.org (J.T. Tretter). Australasian College of Surgeons and a Postgraduate Scholarship from the †The corresponding author of the original article [1] was invited to reply but did National Health and Medical Research Council [grant number 1134340] not respond. to E.B. doi:10.1093/ejcts/ezx473 Advance Access publication 26 December 2017 REFERENCES [1] Nathan M, Emani S, IJsselhof R, Liu H, Gauvreau K, Del Nido P. Mid-term outcomes in unbalanced complete atrioventricular septal defect: role of biventricular conversion from single-ventricle palliation. Eur J Cardiothorac Does biventricular conversion bring survival Surg 2017;52:565–72. [2] d’Udekem Y, Xu MY, Galati JC, Lu S, Iyengar AJ, Konstantinov IE et al. beneﬁts to patients with an unbalanced Predictors of survival after single-ventricle palliation: the impact of right ventricular dominance. J Am Coll Cardiol 2012;59:1178–85. atrioventricular septal defect? [3] Buratto E, Ye XT, King G, Shi WY, Weintraub RG, D’Udekem Y et al. Long- term outcomes of single ventricle palliation for unbalanced atrioventricular a,b,c a a a,b,c, Edward Buratto , Brandon Khoo ,Xin Tao Ye and Igor E. Konstantinov * septal defects: Fontan survivors do better than previously thought. J Thorac Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne, Cardiovasc Surg 2017;153:430–8. VIC, Australia [4] Buratto E, Ye XT, Brizard CP, Brink J, D’udekem Y, Konstantinov IE. Department of Paediatrics, The University of Melbourne, Parkville, VIC, Successful atrioventricular valve repair improves long-term outcomes in Australia children with unbalanced atrioventricular septal defect. J Thorac Murdoch Children’s Research Institute, Melbourne, VIC, Australia Cardiovasc Surg 2017;154:2019–27. [5] King G, Gentles TL, Winlaw DS, Cordina R, Bullock A, Grigg LE et al. Received 11 November 2017; accepted 18 December 2017 Common atrioventricular valve failure during single ventricle palliation. Eur J Cardiothorac Surg 2017;51:1037–43. Keywords: Unbalanced atrioventricular septal defect � Single ventricle palli- ation � Fontan *Corresponding author. Department of Cardiac Surgery, Royal Children’s We read with great interest the recent paper by Nathan et al. [1] published in Hospital, Flemington Road, Parkville, VIC 3029, Australia. Tel: +61-3-93455200; this journal. The authors presented a cohort of 212 patients with unbalanced fax: +61-3-93456386; e-mail: igor.konstantinov@rch.org.au (I.E. Konstantinov). atrioventricular septal defects (uAVSDs), comparing the results of 3 different surgical strategies: single-ventricle palliation (SVP; 82 patients), biventricular doi:10.1093/ejcts/ezx498 repair (67 patients) and biventricular conversion or recruitment (BiVC/BiVR; Advance Access publication 19 January 2018 Downloaded from https://academic.oup.com/ejcts/article-abstract/53/6/1295/4818261 by Ed 'DeepDyve' Gillespie user on 20 June 2018 LETTERS TO THE EDITOR
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Abstract

Letters to the Editor / European Journal of Cardio-Thoracic Surgery 1295 Yu et al. [1] are congratulated on their achievement of successfully closing al- 63 patients). They reported signiﬁcantly better survival with both biventricular legedly doubly committed ventricular septal defects in their series of 35 chil- repair and BiVC/BiVR strategies compared with SVP. dren recently reported in the journal. However, can we be sure that the However, their comparison was biased in favour of the BiVC/BiVR group in defects in question were truly doubly committed and juxta-arterial? The cri- several ways. Their time series analysis began at the time of ﬁrst stage palli- terion stated by the authors for diagnosis in this fashion was that the defect ation for SVP patients, while it began at the time of complete repair for BiVR/ should be ‘located at the 12.00 to 1.30 o’clock position in the parasternal BiVC patients, introducing a substantial survivorship bias. All patients who short axis view’. The criterion for diagnosis of the doubly committed and died prior to conversion were counted in the SVP group, leaving a selected juxta-arterial defect, however, is dependent on its borders rather than its lo- group of survivors to undergo BiVC/BiVR. Furthermore, patients who under- cation. However, the doubly committed variant is one of the defects that went SVP had higher rates of RV dominance (86.6% vs 61.9%), which had pre- can open to the outﬂow tract of the right ventricle and hence be detected viously been shown as a risk factor for death in SVP [2]. The SVP group also ‘in the 12.00 to 1.30 o’clock position’. In our recent experience in Cincinnati, had a much greater proportion of neonates (68.3% vs 3.2%), pulmonary vein of the defects detected on the basis of ‘conal hypoplasia’ and opening to the disease (31.7% vs 22.2%) and associated cardiac anomalies (43.9% vs 27.0%), right ventricle in this position when assessed echocardiographically, only a all of which have been associated with mortality. It is likely that the highly se- proportion was found to be doubly committed based on their borders, spe- lected group undergoing BiVC/BiVR would have had similarly good results ciﬁcally with ﬁbrous continuity between the leaﬂets of the aortic and pul- with the Fontan circulation. monary valves forming their cranial margin. It is not possible to distinguish In Melbourne, SVP is performed for patients with uAVSD who are not can- this feature of ﬁbrous continuity between the leaﬂets of the aortic and pul- didates for initial biventricular repair. We have recently published the long- monary valves in Fig. 3 as provided by Yu et al. [1]. The defects illustrated term outcomes of 139 uAVSD patients who underwent SVP [3]. We observed could just as well have been muscular outlet defects or perimembranous de- a similar attrition to Nathan et al. in the overall cohort, with a survival rate of fects with outlet extension. Because another criterion for exclusion was size 61.8% at 15 years. However, patients who achieved Fontan completion had <5 mm, it seems that the defects could have possessed completely muscular much better results than previously thought, with 83.5% freedom from death borders, and more so since the authors describe the pulmonary ‘annulus’ as and Fontan takedown at 15 years. This is similar to the results for BIVC/BiVR being ‘slightly higher than the aortic annulus’ in their patients. Had the de- reported by Nathan et al.[1], and it is likely that this cohort includes a similar fects truly been doubly committed, then the so-called ‘annuluses’ would degree of survivorship bias. have been at the same level. We do not mean to question the efﬁcacy of the Importantly, we observed that atrioventricular valve (AVV) regurgitation method proposed by the Chinese authors. If it is to be more widely used, is a major contributor to morbidity and mortality observed in these patients nonetheless, then surely it is crucial to provide more precise details of the [4, 5]. Patients with AVV regurgitation who achieved successful repair had criteria used so as to diagnose the defects as being doubly committed and much better outcomes than those with a signiﬁcant residual regurgitation [4]. juxta-arterial? Our focus is on improving the outcomes of AVV repair in these patients, as we believe this will be the key to improved survival. The work by Nathan et al. is important, and their results are encouraging. However, we emphasize that palliation with the Fontan circulation remains an REFERENCE important option for these patients. Advancements in techniques for repairing the AVV might further improve the outcomes for patients with uAVSD who [1] Yu J, Ma L, Ye J, Zhang Z, Li J, Yu J et al. Doubly committed ventricular sep- undergo SVP. tal defect closure using eccentric occlude via ultraminimal incision. Eur J Cardiothorac Surg 2017;52:805–9. Funding *Corresponding author. Cincinnati Children’s Hospital Medical Center, The Heart Institute, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. Tel: 513-803- This work was supported by a Reg Worcester Scholarship from the Royal 4538; e-mail: justin.tretter@cchmc.org (J.T. Tretter). Australasian College of Surgeons and a Postgraduate Scholarship from the †The corresponding author of the original article [1] was invited to reply but did National Health and Medical Research Council [grant number 1134340] not respond. to E.B. doi:10.1093/ejcts/ezx473 Advance Access publication 26 December 2017 REFERENCES [1] Nathan M, Emani S, IJsselhof R, Liu H, Gauvreau K, Del Nido P. Mid-term outcomes in unbalanced complete atrioventricular septal defect: role of biventricular conversion from single-ventricle palliation. Eur J Cardiothorac Does biventricular conversion bring survival Surg 2017;52:565–72. [2] d’Udekem Y, Xu MY, Galati JC, Lu S, Iyengar AJ, Konstantinov IE et al. beneﬁts to patients with an unbalanced Predictors of survival after single-ventricle palliation: the impact of right ventricular dominance. J Am Coll Cardiol 2012;59:1178–85. atrioventricular septal defect? [3] Buratto E, Ye XT, King G, Shi WY, Weintraub RG, D’Udekem Y et al. Long- term outcomes of single ventricle palliation for unbalanced atrioventricular a,b,c a a a,b,c, Edward Buratto , Brandon Khoo ,Xin Tao Ye and Igor E. Konstantinov * septal defects: Fontan survivors do better than previously thought. J Thorac Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne, Cardiovasc Surg 2017;153:430–8. VIC, Australia [4] Buratto E, Ye XT, Brizard CP, Brink J, D’udekem Y, Konstantinov IE. Department of Paediatrics, The University of Melbourne, Parkville, VIC, Successful atrioventricular valve repair improves long-term outcomes in Australia children with unbalanced atrioventricular septal defect. J Thorac Murdoch Children’s Research Institute, Melbourne, VIC, Australia Cardiovasc Surg 2017;154:2019–27. [5] King G, Gentles TL, Winlaw DS, Cordina R, Bullock A, Grigg LE et al. Received 11 November 2017; accepted 18 December 2017 Common atrioventricular valve failure during single ventricle palliation. Eur J Cardiothorac Surg 2017;51:1037–43. Keywords: Unbalanced atrioventricular septal defect � Single ventricle palli- ation � Fontan *Corresponding author. Department of Cardiac Surgery, Royal Children’s We read with great interest the recent paper by Nathan et al. [1] published in Hospital, Flemington Road, Parkville, VIC 3029, Australia. Tel: +61-3-93455200; this journal. The authors presented a cohort of 212 patients with unbalanced fax: +61-3-93456386; e-mail: igor.konstantinov@rch.org.au (I.E. Konstantinov). atrioventricular septal defects (uAVSDs), comparing the results of 3 different surgical strategies: single-ventricle palliation (SVP; 82 patients), biventricular doi:10.1093/ejcts/ezx498 repair (67 patients) and biventricular conversion or recruitment (BiVC/BiVR; Advance Access publication 19 January 2018 Downloaded from https://academic.oup.com/ejcts/article-abstract/53/6/1295/4818261 by Ed 'DeepDyve' Gillespie user on 20 June 2018 LETTERS TO THE EDITOR